Strain-encoded Cardiac Magnetic Resonance Research Articles

Layer-specific fast strain-encoded cardiac magnetic resonance imaging aids in the identification and discrimination of acute myocardial injury: a prospective proof-of-concept study

Acute myocardial injury is a common diagnosis in the emergency department and differential diagnoses are numerous. Cardiac magnetic resonance (CMR) strain sequences, such as fast strain ENCoded (fSENC), are early predictors of myocardial function loss. This study assessed the potential diagnostic and prognostic benefits of a layer-specific approach. For this prospective study, patients in the emergency department fulfilling rule-in criteria for non-ST-elevation myocardial infarction (NSTEMI) received an ultra-fast fSENC CMR. Volunteers without cardiac diseases (controls) were recruited for comparison. Measurements were performed in a single heartbeat acquisition to measure global longitudinal strain (GLS) and segmental longitudinal strain and dysfunctional segments. The GLS was measured in two layers and a difference (GLSdifference =GLSepicardial -GLSendocardial) was calculated. The performance of those strain features was compared to standard care (physical examination, cardiac biomarkers, electrocardiogram). According to the final diagnosis after discharge, patients were divided into groups and followed up for 2years. A total of 114 participants, including 50 controls, were included. The 64 patients (51 male) were divided into a NSTEMI (25), myocarditis (16), and other myocardial injury group (23). GLS served as a potent predictor of myocardial injury (area under the curve (AUC) 91.8%). The GLSdifference provided an excellent diagnostic performance to identify a NSTEMI (AUC 83.2%), further improved by including dysfunctional segments (AUC 87.5%, p=0.01). An optimal test was achieved by adding fSENC to standard care (AUC 95.5%, sensitivity 96.0%, specificity 86.5%, p=0.03). No death occurred in 2years for patients with normal GLS and ≤5 dysfunctional segments, while three patients died that showed abnormal GLS or >5 dysfunctional segments. Layer-specific strain is a potential new marker with high diagnostic performance in the identification and differentiation of acute myocardial injuries.

Layer-specific circumferential strain using fast strain-encoded cardiac magnetic resonance imaging in acute myocardial injury - a prospective study of diagnostic and prognostic accuracy

Abstract Background In patients presenting acutely with chest pain or shortness of breath, an acute myocardial injury diagnosed through modern troponin assays is common. Yet, a differential diagnosis is often demanding and must weigh the timely treatment of an ischemic cause against the risk of an invasive procedure without intervention. Modern cardiac magnetic resonance (CMR) strain sequences such as fast-SENC (fSENC) might support clinical decision-making in identifying predictors of myocardial dysfunction (1). Furthermore, their resolution should be able to differentiate epicardial from endocardial function impairment. This study sought to assess a layer-specific strain approach's diagnostic and prognostic accuracy using circumferential strain. Methods In this board-approved prospective observational study, patients from the emergency department fulfilling rule-in criteria for NSTEMI according to current guidelines received an ultra-fast fSENC CMR independently of standard care (2,3). fSENC was acquired in a single heartbeat acquisition, and global/segmental circumferential strain (GCS) as well as dysfunctional segments were measured. GCS was measured in two layers (epicardial/endocardial = GCSepi/GCSendo). Patients were followed up for two years for the occurrence of cardiovascular death and divided into groups according to their final diagnosis upon discharge. Results 64 patients (51 male) were included, consisting of 25 with NSTEMI, 16 with myocarditis and 23 with other causes of myocardial injury (OMI). GCS was reduced in all patients but with no significant difference between groups (NSTEMI: -14.3±3.8; myocarditis: 15.9±4.6; OMI: 13.9±3.8; p>0.05). GCSendo (-16.3±4.0) was generally lower than GCSepi (-12.5±3.1) in all groups (p < 0.001), but did not differ between groups (p>0.05). Overall, 2-year mortality was low (4.7%). Nevertheless, GCSendo predicted outcome (p = 0.03), unlike GCS. 2-year survival in patients with normal GCS (>-17%) and ≤5 dysfunctional segments was 100.0%. Conclusions Layer-specific circumferential strain is a significant predictor of prognosis. Endo- and epicardial strain is reduced in all types of myocardial injury. For the identification of underlying pathology however, layer-specific circumferential strain did not add incremental value.

57884 Fast strain-encoded cardiac magnetic resonance detects immune checkpoint inhibitor associated cardiotoxicity

ABSTRACT IMPACT: Advanced cardiac magnetic resonance imaging techniques can help to protect cancer patients from cardiotoxicity from immunotherapy with a more sensitive assessment of cardiac function with strain imaging for detection of abnormal cardiac function in the setting of normal left ventricular ejection fraction. OBJECTIVES/GOALS: Immune checkpoint inhibitors (ICI) are associated with fatal cardiotoxicity. Cardiac magnetic resonance (CMR) imaging can assess ICI-associated cardiotoxicity, but the utility of CMR strain imaging is unknown. We present a study of patients with ICI-associated cardiotoxicity evaluated with fast strain-encoded (fast-SENC) CMR. METHODS/STUDY POPULATION: This prospective study was approved by the institutional IRB and informed consent was obtained from 15 patients (5 patients with ICI-associated cardiotoxicity, 10 controls patients) between August 2018 and January 2020. All patients with ICI-associated cardiotoxicity had abnormal troponin values and evidence of cardiotoxicity on T2-weighted and/or delayed enhancement CMR images. All patients underwent standard CMR assessment with steady state free precession cine images, T2-weighted imaging, and delayed gadolinium enhancement imaging. Additionally, free-breathing SENC images were obtained and then processed by a team of blinded cardiovascular imaging specialists using Myostrain software (Morrisville, USA). RESULTS/ANTICIPATED RESULTS: Left ventricular ejection fraction (LVEF) was normal in both groups (ï,³53%). Global longitudinal LV strain was significantly depressed in the ICI cardiotoxicity group versus controls (-12.8 ±3.2% vs. -16.6 ±1.9%, p=0.028). The average global circumferential LV strain was mildly abnormal (defined as strain > -17) in the ICI cardiotoxicity group and trended towards a higher value compared with controls (-16.0 ±2.6% vs -17.8 ±1.7%, p=0.103). The average number of dysfunctional segments (defined as strain > -10) was significantly higher in the ICI cardiotoxicity group (6.8 ±4.2 vs. 1.0 ±1.7, p=0.017). The proportion of abnormal myocardium was higher in the ICI cardiotoxicity group (66 ±21% vs. 45 ±18%, p=0.050), as well as the proportion of myocardium found to be dysfunctional (26 ±22% vs. 3.0 ±6.0%, p=0.041). DISCUSSION/SIGNIFICANCE OF FINDINGS: Despite having preserved LVEF, patients who met criteria for ICI-associated cardiotoxicity had both global and regional abnormal LV strain. Fast-SENC imaging may provide a sensitive tool for detection of early cardiotoxicity in this population. This study is limited by its small cohort and a larger prospective study would be of value.

Fast Strain-Encoded Cardiac Magnetic Resonance for Diagnostic Classification and Risk Stratification of Heart Failure Patients

ObjectivesThe purpose of this study was to compare the ability of fast-strain encoded magnetic resonance (fast-SENC) cardiac magnetic resonance (CMR) to classify and risk stratify all-comer patients with different stages of chronic heart failure (Stages of heart failure A to D) based on American College of Cardiology/American Heart Association guidelines with standard clinical and CMR imaging data. BackgroundHeart failure is a major cause of morbidity and mortality, resulting in millions of deaths and hospitalizations annually. MethodsThe study population consisted of 1,169 consecutive patients between September 2017 and February 2019 who underwent CMR for clinical reasons, and 61 healthy volunteers. In addition, clinical follow-up was performed in Stages A and B patients after 1.9 ± 0.4 years. Wall motion score and late gadolinium enhancement score indexes, left ventricular (LV) ejection fraction, and global circumferential and longitudinal strain based on fast-SENC acquisitions, were calculated in all subjects. The percentage of myocardial segments with strain ≤−17% (% normal myocardium) was determined in all subjects. ResultsLV ejection fraction, global circumferential and longitudinal strain, and % normal myocardium significantly decreased with increasing heart failure stages (p < 0.001 for all by analysis of variance). By multivariable analysis, % normal myocardium remained an independent predictor of heart failure stages, exhibiting closer association than LV ejection fraction (rpartial = 0.76 vs. rpartial = 0.30; p < 0.001). Importantly, 149 of 399 (37%) with Stage A were reclassified to Stage B, that is, as having subclinical LV dysfunction based on % normal myocardium <80%. Such patients exhibited significantly higher rates of all-cause mortality and hospital stay due to heart failure during follow-up, compared with patients with % normal myocardium ≥80% (chi-square = 6.9; p = 0.03). ConclusionsThe % normal myocardium, determined by fast-SENC, enables improved identification of asymptomatic patients with subclinical LV dysfunction compared with LV ejection fraction and risk stratification of patients with so far asymptomatic heart failure. The identification of such presumably healthy patients at high risk for heart failure-related outcomes may bear important medical implications.

Strain-encoded cardiac magnetic resonance imaging: a new approach for fast estimation of left ventricular function

BackgroundRecently introduced fast strain-encoded (SENC) cardiac magnetic resonance (CMR) imaging (fast-SENC) provides real-time acquisition of myocardial performance in a single heartbeat. We aimed to test the ability and accuracy of real-time strain-encoded CMR imaging to estimate left ventricular volumes, ejection fraction and mass.MethodsThirty-five subjects (12 healthy volunteers and 23 patients with known or suspected coronary artery disease) were investigated. All study participants were imaged at 1.5 Tesla MRI scanner (Achieva, Philips) using an advanced CMR study protocol which included conventional cine and fast-SENC imaging. A newly developed real-time free-breathing SENC imaging technique based on the acquisition of two images with different frequency modulation was employed.ResultsAll parameters were successfully derived from fast-SENC images with total study time of 105 s (a 15 s scan time and a 90 s post-processing time). There was no significant difference between fast-SENC and cine imaging in the estimation of LV volumes and EF, whereas fast-SENC underestimated LV end-diastolic mass by 7%.ConclusionThe single heartbeat fast-SENC technique can be used as a good alternative to cine imaging for the precise calculation of LV volumes and ejection fraction while the technique significantly underestimates LV end-diastolic mass.

PRM33 - Cost-Effectiveness Analysis of Myostrain in Suspected Coronary Artery Disease Patients

The aim of this research is to evaluate the relative cost-effectiveness of strain-encoded cardiac magnetic resonance imaging (MyoStrain) and single-photon emission coronary tomography (SPECT) as the first line of noninvasive diagnostic modality in patients presenting with chest pain. We developed a decision-analytical model, comparing sequential tests for evaluating patients with possible stable angina and a state-transition (Markov) model to capture coronary artery disease (CAD) progression along with costs and outcomes of CAD diagnostic strategies. The model assumed a typical U.S. health payer perspective, was based on a hypothetical patient cohort with the pretest probability of coronary artery disease (CAD) between 20% and 70%. Comprehensive literature review provided the input data for test accuracy and the long-term prognosis. Resource utilization and cost data were derived from literature, hospital cost database and Medicare reimbursement rates. The diagnostic strategy using MyoStrain generated less frequent false positive initial tests and false negative final diagnosis. MyoStrain’s cost effectiveness is dominant to SPECT, and MyoStrain showed an improved quality of life compared to SPECT. In patients with CAD prevalence of 20% to 70%, MyoStrain is more cost-effective than SPECT. MyoStrain also improves quality of life while reducing unnecessary radiation and cancer risk in patients presenting with chest pain.

24 Peak circumferential strain assessed using strain-encoded cardiac magnetic resonance (dense) in healthy volunteers at 1.5- and 3.0 TESLA: Abstract 24 Table 1

<h3>Background</h3> Displacement Encoding with Stimulated Echoes (DENSE) is a strain-encoded cardiac magnetic resonance (CMR) method that directly quantifies left ventricular (LV) mechanics within myocardial regions. Strain values might vary according to CMR field strength. In order to assess this possibility, we implemented strain-encoded CMR at 1.5 Tesla and 3.0 Tesla with DENSE in healthy adults. <h3>Methods</h3> Healthy volunteers without any medical history or treatment gave informed consent and underwent CMR at 1.5T (Magnetom Avanto, Siemens Healthcare) and 3.0T (Magnetom Verio; Siemens Healthcare) within 24 h. The imaging protocol included balanced steady state free precession (b-SSFP) sequences for cardiac anatomy and function and strain-encoded CMR with DENSE. (CIM_DENSE2D software (University of Auckland, New Zealand; Siemens Healthcare). Global- and segmental circumferential strain was measured at the mid-ventricular level. <h3>Results</h3> Sixty five participants (31 (48%) male, mean age 44 ± 18) were included (Table 1). Mean global and regional strain values differed slightly between 1.5T and 3.0T, and these differences were mainly related to strain values in the anterior and anterolateral LV segments were LV displacement is greatest. <h3>Conclusion</h3> Strain-encoded CMR with DENSE provides regionally localised measurements of circumferential strain. Subtle field-strength differences were apparent for anterior/antero-lateral LV strain. <h3>Funding</h3> Medical Research Scotland project grant. Professor Berry was supported by a Senior Clinical Fellowship from the Scottish Funding Council.

10 Sex differences in circumferential and longitudinal strain revealed by strain-encoded cardiac magnetic resonance in healthy volunteers at 1.5T: Abstract 10 Table 1

<h3>Background</h3> Displacement encoding with stimulated echoes (DENSE) encodes myocardial tissue displacement into the phase of the MRI image, thus allowing direct quantification of myocardial displacement at multiple cardiac phases. Strain-encoded CMR with DENSE has high spatial (3.2 × 3.2 × 8 mm) and temporal resolution (32.5 ms phase). We aimed to measure myocardial strain values with DENSE in healthy adults across a broad age range at 1.5 Tesla. <h3>Methods</h3> Healthy volunteers with no prior medical history (including cardiovascular health problems or medication) were enrolled and underwent CMR at 1.5T (Magnetom Avanto, Siemens Healthcare, Erlangen, Germany). Mid-left ventricular short axis and horizontal long axis DENSE sequences were obtained, and analysed using CIM_DENSE2D software (University of Auckland, New Zealand and Siemens Healthcare). Segmental and global myocardial circumferential and longitudinal strain were obtained. <h3>Results</h3> LV dimensions and circumferential strain were available for 75 volunteers (mean age 44.12 ± 17.7 years old, 48% male) (Table 1). Longitudinal strain was acquired in a subset of participants (n = 20). Mean global circumferential (Ecc) and longitudinal (Ell) strain were greater in women than in men. These differences were mainly related to strain values in the inferior, infero-lateral and antero-lateral LV segments for the circumferential strain and the apico-lateral segment for the longitudinal strain where LV displacement is greatest. <h3>Conclusion</h3> Strain-encoded CMR with DENSE has revealed sex differences in myocardial contractility in healthy adults. <h3>Funding</h3> Medical Research Scotland project grant. Professor Berry was supported by a Senior Clinical Fellowship from the Scottish Funding Council.

23 Longitudinal but not circumferential strain is associated with healthy ageing: a strain-encoded cardiac magnetic resonance imaging study at 3.0TESLA: Abstract 23 Table 1

Background Displacement encoding with stimulated echoes (DENSE) encodes myocardial tissue displacement into the phase of the MRI image permitting direct quantification of myocardial displacement at multiple cardiac phases. Strain-encoded CMR with DENSE has high spatial (3.2 mm × 3.2 mm × 8 mm) and temporal resolution (TR= 27.34 ms). We aimed to measure myocardial strain values with DENSE in healthy adults across a broad age range at 3.0Tesla. Methods Healthy volunteers with no prior medical history or treatment were enrolled and underwent CMR at 3.0T (Magnetom Verio, Siemens, Erlangen, Germany). Mid-left ventricular short axis and horizontal long axis DENSE sequences were obtained, and analysed using CIM_DENSE2D software (University of Auckland, New Zealand and Siemens Healthcare). Segmental and global myocardial circumferential (Ecc) and longitudinal (Ell) strain were obtained with DENSE. Results 77 participants (mean (SD) age 43.0(16.9) years; range 18–78 years; 40 (52%) males;) were grouped into 3 tertiles according to age. Longitudinal strain differed according to age tertile with strain being greatest in individuals 35–55 years compared to younger or older subjects. There were no differences in Ecc according to age per tertile (Table 1). Conclusion Longitudinal myocardial strain, as revealed by strain-encoded CMR, is associated with chronological age in healthy adults. Funding Medical Research Scotland project grant. Professor Berry was supported by a Senior Clinical Fellowship from the Scottish Funding Council.

Quantitative Analysis of Endocardial and Epicardial Left Ventricular Myocardial Deformation—Comparison of Strain-Encoded Cardiac Magnetic Resonance Imaging with Two-Dimensional Speckle-Tracking Echocardiography

Quantitative analysis of segmental myocardial deformation of different myocardial layers has become possible using strain-encoded cardiac magnetic resonance imaging (SENC) and speckle-tracking echocardiography (STE). We evaluated and compared the quantitative analysis of myocardial deformation using SENC and STE. In 44 patients (age 61 ± 13 years, 34 men), SENC by cardiac magnetic resonance imaging using a 1.5-Tesla whole-body scanner and two-dimensional STE were performed prospectively. Quantitative layer-specific analysis of segmental left ventricular function was performed to determine the peak circumferential and peak longitudinal systolic strain values using SENC and STE of an endocardial and epicardial myocardial layer. In addition, segmental function was defined as normokinetic, hypokinetic, or akinetic by visual analysis of the magnetic resonance imaging cine sequences. The endocardial and epicardial strain defined by SENC or STE differed significantly between the visually defined segmental function states. The correlation of the peak circumferential endocardial strain by SENC versus STE (intraclass correlation coefficient [ICC] 0.493, 95% CI 0.358-0.597) tended to be better than the correlation of the circumferential epicardial strain using both methods (ICC 0.321, 95% CI 0.238-0.399). The correlation of the peak longitudinal endocardial strain by SENC and STE was similar (ICC 0.472, 95% CI 0.398-0.541), in contrast to the longitudinal epicardial strain analysis by both techniques (ICC 0.554, 95% CI 0.417-0.655). Circumferential strain analysis by STE allowed better distinction of the hypokinetic or akinetic segments from the normokinetic segments than did the circumferential strain analysis by SENC of the endocardial layer (area under the receiver operating characteristic curve [AUC ROC] 0.946 vs 0.884; P < .001) or epicardial layer (AUC ROC 0.884 vs 0.782; P < .001). Longitudinal strain analysis using STE and SENC of theendocardial layer (AUC ROC 0.851 vs 0.839; P= .5838) and epicardial layer (AUC ROC 0.849 vs 0.833; P= .4321) had similar diagnostic value for identifying the presence of hypokinetic and akinetic segments. Quantitative analysis of segmental deformation by SENC and STE allowed accurate distinction of myocardial segments with different functional states. Circumferential endocardial strain analysis by STE allowed the best distinction of segments with impaired function from the normokinetic segments.

Strain-Encoded Cardiac Magnetic Resonance During High-Dose Dobutamine Stress Testing for the Estimation of Cardiac Outcomes: Comparison to Clinical Parameters and Conventional Wall Motion Readings

The purpose of this study was to determine the prognostic value of strain-encoded magnetic resonance imaging (SENC) during high-dose dobutamine stress cardiac magnetic resonance imaging (DS-MRI) compared with conventional wall motion readings. Detection of inducible ischemia by DS-MRI on the basis of assessing cine images is subjective and depends on the experience of the readers, which may influence not only the diagnostic classification but also the risk stratification of patients with ischemic heart disease. In all, 320 consecutive patients with suspected or known coronary artery disease underwent DS-MRI, using a standard protocol in a 1.5T MR scanner. Wall motion abnormalities (WMA) and myocardial strain were assessed at baseline and during stress, and outcome data including cardiac deaths, nonfatal myocardial infarctions ("hard events"), and revascularization procedures performed >90 days after the MR scans were collected. Thirty-five hard events occurred during a 28 ± 9 month follow-up period, including 10 cardiac deaths and 25 nonfatal myocardial infarctions, and 32 patients underwent coronary revascularization. Using a series of Cox proportional-hazards models, both resting and inducible WMA offered incremental information for the assessment of hard cardiac events compared to clinical variables (chi-square = 13.0 for clinical vs. chi-square = 26.1 by adding resting WMA, p < 0.001, vs. chi-square = 39.3 by adding inducible WMA, p < 0.001). Adding visual SENC or quantitative strain rate reserve to this model further improved the prediction of outcome (chi-square = 50.7 vs. chi-square = 52.5, p < 0.001 for both). In a subset of patients (n = 175) who underwent coronary angiography, SENC yielded significantly higher sensitivity for coronary artery disease detection (96% vs. 84%, p < 0.02), whereas specificity and accuracy were not significantly different (88% vs. 94% and 93% vs. 88%, p = NS for both). Strain-encoded MRI aids the accurate identification of patients at high risk for future cardiac events and revascularization procedures, beyond the assessment of conventional atherogenic risk factors and resting or inducible WMA on cine images. (Strain-Encoded Cardiac Magnetic Resonance Imaging as an Adjunct for Dobutamine Stress Testing; NCT00758654).

Strain-encoded cardiac magnetic resonance during high-dose dobutamine stress testing for the estimation of cardiac outcomes. Comparison to clinical parameters and conventional wall motion readings

DS-MRI is a well established modality for the diagnostic classification and the risk stratification of patients with coronary artery disease (CAD). However, currently the detection of inducible ischemia by DS-MRI is based on the assessment of cine images, which is subjective and depends on the experience of the readers. In this regard, the human eye primarily tracks the radial displacement of the myocardium with cine-images, which is less sensitive than circumferential and longitudinal components for the detection of myocardial dysfunction.

Strain-Encoded CMR for the Detection of Inducible Ischemia During Intermediate Stress

This study sought to evaluate the diagnostic accuracy of strain-encoded cardiac magnetic resonance (SENC) for the detection of inducible ischemia during intermediate stress. High-dose dobutamine stress cardiac magnetic resonance (DS-CMR) is a well-established modality for the noninvasive detection of coronary artery disease (CAD). However, the assessment of cine scans relies on the visual interpretation of wall motion, which is subjective, and modalities that can objectively and quantitatively assess the time course of myocardial strain response during stress are lacking. Stress-induced ischemia was assessed by wall motion analysis and by SENC in 80 patients with suspected or known CAD and in 18 healthy volunteers who underwent DS-CMR in a clinical 1.5-T scanner. Quantitative coronary angiography was used as the standard reference for the presence of CAD (> or =50% diameter stenosis). On a patient level, 46 of 80 patients (58%) had CAD, including 20 with single-vessel, 18 with 2-vessel, and 8 with 3-vessel disease. During peak stress, SENC correctly detected ischemia in 45 versus 38 of 46 patients with CAD (7 additional correct findings for SENC), yielding significantly higher sensitivity than cine (98% vs. 83%, p < 0.05). No patients were correctly diagnosed by cine and missed by SENC. During intermediate stress, SENC showed diagnostic value similar to that provided by cine imaging only during peak dobutamine stress (sensitivity of 76% vs. 83%, specificity of 88% vs. 91%, and accuracy of 81% vs. 86%; p = NS for all). Quantification analysis demonstrated that strain rate response is a highly sensitive marker for the detection of inducible ischemia (area under the curve = 0.96; SE = 0.01; 95% confidence interval: 0.93 to 0.99) that precedes the development of inducible wall motion abnormalities and already significantly decreases with moderate 40% to 60% coronary lesions. Using SENC, CAD can be detected during intermediate stress with similar accuracy to that provided by cine only during peak stress. By this approach, patient safety may be improved during diagnostic procedures within lower time spent (Strain-Encoded Cardiac Magnetic Resonance Imaging for Dobutamine Stress Testing; NCT00758654).

Multimodality Noninvasive Imaging for Assessment of Congenital Heart Disease

Major advances in the field of pediatric cardiology and cardiac surgery over the last several decades have led to a dramatic improvement in survival rates for most forms of congenital heart disease (CHD). For example, hypoplastic left heart syndrome, a previously lethal defect, now has early survival rates up to 90% at major centers.1 These improved outcomes have produced a growing population of survivors with complex CHD who are now reaching adulthood (Figure 1). During this period, improvements in surgical and medical treatments have been accompanied by developments in diagnostic modalities. Echocardiography has replaced catheterization as the primary diagnostic modality, and it is now uncommon for newborn infants to undergo catheterization for purely diagnostic purposes. Although echocardiography remains the bedrock of noninvasive cardiac imaging, the array of diagnostic modalities and techniques available continue to grow and this has spawned the specialty of “noninvasive cardiac imaging” and the need for the “cardiac imager” to be adept in all the different modalities. Figure 1. Percentage of patients under the age of 1 year (grey bars) and over the age of 18 years (black bars) undergoing echocardiography at Children’s Hospital Boston from 1983 through 2006. Note the reverse trends of these age groups reflecting the steady increase in the proportion of adult patients with congenital heart disease. Although the absolute number of infants undergoing echocardiography during this time period has increased, their proportion has steadily declined. Echocardiography, cardiac magnetic resonance (CMR), and cardiac computed tomography (CCT) are the primary modalities used for noninvasive cardiac imaging in patients with CHD. Nuclear scintigraphy is used in selected circumstances. The Table summarizes the strengths and weaknesses of each modality. Figure 2 shows temporal trends in utilization for the various noninvasive cardiac imaging techniques at our center. It is clear that echocardiography is the most frequently …

Strain-Encoded Cardiac Magnetic Resonance for the Evaluation of Chronic Allograft Vasculopathy in Transplant Recipients

The aim of our study was to investigate the ability of Strain-Encoded magnetic resonance imaging (MRI) to detect cardiac allograft vasculopathy (CAV) in heart transplantation (HTx)-recipients. In consecutive subjects (n = 69), who underwent cardiac catheterization, MRI was performed for quantification of myocardial strain and perfusion reserve. Based on angiographic findings subjects were classified: group A including patients with normal vessels; group B, patients with stenosis <50%; and group C, patients with severe CAV (stenosis >or= 50%). Significant correlations were observed between myocardial perfusion reserve with peak systolic strain (r =-0.53, p < 0.001) and with mean diastolic strain rate (r = 0.82, p < 0.001). Peak systolic strain and strain rate were significantly reduced only in group C, while mean diastolic strain rate and myocardial perfusion reserve were already reduced in group B and A. Myocardial perfusion reserve and mean diastolic strain rate had higher accuracy for the detection of CAV (AUC = 0.95, 95% CI = 0.87-0.99 and AUC = 0.93, 95% CI = 0.84-0.98, respectively) and followed peak systolic strain and strain rate (AUC = 0.80, 95% CI = 0.69-0.89 and AUC = 0.78, 95% CI = 0.67-0.87, respectively). Besides the quantification of myocardial perfusion, the estimation of the diastolic strain rate is a useful parameter for CAV assessment. In combination with the clinical evaluation, these parameters may be effective tools for the routine surveillance of HTx-recipients.